TW201920802A - Sizing agent for reinforcing fiber and use thereof - Google Patents

Abstract

The present invention provides a sizing agent for reinforcing fibers and a synthetic fiber strand and fiber reinforced composite material using the same, the sizing agent for reinforcing fibers capable of simultaneously imparting excellent fiber bundling properties, excellent scratch resistance, excellent uniform adhesion, and excellent adhesion to a matrix resin to reinforcing fibers used for reinforcing the matrix resin. The sizing agent for reinforcing fiber comprises a polyamide (A), a carbodiimide group-containing compound (B), and water (C), wherein the polyamide (A) has a melt viscosity at 150 DEG C of 100 to 15,000 mPa.s and the compound (B) has two or more carbodiimide groups in the molecule. Preferably, the polyamide (A) is a water soluble polyamide.

Description

Sizing agent for reinforcing fibers and its use

The present invention relates to a sizing agent for reinforcing fibers and its use. Specifically, it relates to a sizing agent for reinforcing fibers used to reinforce a matrix resin, and a synthetic fiber yarn and a fiber-reinforced composite material using the sizing agent for reinforcing fibers.

Among the above matrix resins, polyolefin resins, polyamide resins, polycarbonate resins, polyacetal resins, ABS resins, polyphenylene sulfide resins, and polyethers have attracted attention due to their ease of molding and favorable recycling. In the case of thermoplastic resins such as rhenium imine resins and fiber-reinforced composite materials using such thermoplastic resins, reinforcing fibers are generally used in the form of staple fibers cut into lengths of 1 to 15 mm. When manufacturing the pellets obtained by kneading the staple fiber and the thermoplastic resin, the bundling property of the staple fiber is very important. If the bundling property is not appropriate, the supply of the staple fiber will be unstable, the yarn will break, and the like will be reduced. Physical properties of the obtained composite material. In order to prevent this, many techniques for imparting a sizing agent based on various thermoplastic resins have been proposed for the purpose of imparting appropriate bundling properties to fibers (see Patent Document 1), and they are widely used in industry.

In addition, depending on the reinforcing fiber, there are those with a small elongation and brittleness. Such reinforcing fibers provided to a conventional sizing agent have problems such as fluff or fiber breakage due to mechanical friction and the like in the processing steps.

In addition, in order to obtain the high physical properties of the fiber-reinforced composite material, the adhesiveness of the matrix resin and the sizing agent and the uniform adhesion of the sizing agent are very important. For example, Patent Document 2 proposes a thermoplastic sizing agent with excellent operability and adhesion. However, the sizing agent disclosed in this patent document requires an additional heat treatment step after the drying step, which causes problems such as an increase in equipment costs and a reduction in productivity. .

In order to obtain sufficient adhesion strength and film strength, it is necessary to increase the molecular weight of the resin component in the sizing agent (see Patent Document 3). However, such a sizing agent has a high molecular weight of the resin in the sizing agent. Therefore, the resin has a high viscosity and a low fluidity when applied to fibers, and there is a problem that sufficient wettability and uniform adhesion cannot be obtained. That is, the adhesiveness between the sizing agent and the matrix resin, and the wettability and uniform adhesion of the sizing agent are opposite properties. That is, recently, the use and usage of fiber-reinforced composite materials are required to be diversified, and mechanical strength is further required. The use of the sizing agent described in the prior art has the following problems: the bundling and abrasion resistance of fibers, and All the properties required for the uniform adhesiveness of the slurry and the adhesiveness with the matrix resin did not reach a satisfactory level at the same time.

[Prior technical literature] [Patent Literature]

Patent Document 1: Japanese Patent Application Publication No. 2007-131959.

Patent Document 2: Japanese Patent Publication No. 05-004348.

Patent Document 3: Japanese Patent No. 4229534.

In view of the past technical background, an object of the present invention is to provide a sizing agent for reinforcing fibers, which can simultaneously provide excellent fiber bundling, excellent abrasion resistance, excellent uniform adhesion to reinforcing fibers used to reinforce matrix resin, And excellent adhesion to the matrix resin, and provide a synthetic fiber yarn and a fiber-reinforced composite material using the sizing agent for reinforcing fibers.

The present inventors made an effort to review the above-mentioned problems, and as a result, found that the sizing agent for reinforcing fibers containing polyamine having a specific melt viscosity, a specific carbon diimide group-containing compound, and water can solve the above problems.

That is, the present invention is a sizing agent for reinforcing fibers, which contains polyamidoamine (A), a carbodiimide-containing compound (B), and water (C). The polyamidoamine (A) is 150 The melt viscosity at ℃ is 100 to 15000mPa. s. The compound (B) has two or more carbodiimide groups in the molecule.

The polyfluorene (A) is preferably a water-soluble polyamine. The polyamidoamine (A) is preferably a polycondensate of an amine and a carboxylic acid, and has an oxyalkylene group. The weight ratio (B / A) of the aforementioned carbodiimide-containing compound (B) is preferably 1 to 30% by weight relative to the aforementioned polyamidoamine (A).

The amount of the chemical formula of the aforementioned carbodiimide-containing compound (B) per 1 mol of the carbodiimide group is preferably 300 to 600.

The reinforcing fiber yarn of the present invention is obtained by attaching the above-mentioned sizing agent for reinforcing fibers to a raw material reinforcing fiber yarn. Aforementioned reinforcing fiber Carbon fiber is preferred.

The fiber-reinforced composite material of the present invention contains a matrix resin and the above-mentioned reinforcing fiber threads. The matrix resin is preferably a thermoplastic resin.

The sizing agent for reinforcing fibers of the present invention can simultaneously impart excellent fiber bundling properties, excellent abrasion resistance, excellent uniform adhesion, and excellent adhesion to the matrix resin to the reinforcing fibers used to reinforce the matrix resin.

Each component of the sizing agent for reinforcing fibers of this invention is demonstrated in detail.

[Polyamide (A)]

Polyamide (A) is a component that imparts fiber bundling, abrasion resistance, and uniform adhesion as a sizing agent for reinforcing fibers of the present invention. Polyamide (A) is a component that imparts fiber bundling, abrasion resistance, and uniform adhesion. The reason has not yet been determined. The reason is presumed to be as follows: The film is filmed and covered to protect the fiber bundle during drying, thereby imparting fiber bundling property. Also, because it has a specific melt viscosity, it has high fluidity and uniformly adheres to fibers, thereby suppressing fluff.

The melt viscosity of polyamidoamine (A) at 150 ° C is preferably 100 to 15000 mPa. s, more preferably 500 to 10000 mPa. s, and more preferably 1000 to 8000 mPa. s. Less than 100mPa. At s, the strength of the dried film is weak and the bunching property is insufficient, if it exceeds 15000mPa. s, the fluidity of polyamine (A) is low, and uniform adhesion and abrasion resistance are insufficient.

The ratio of the amount of the terminal carboxyl group to the amount of the terminal amine group of the polyamidoamine (A) is not particularly limited. From the viewpoint of reactivity with a carbodiimide compound described later, it is preferably 60/40 to 100/0, more preferably It is preferably 70/30 to 90/10. The amount of terminal carboxyl groups can be calculated by measuring the acid value of the polyamide resin, and the amount of terminal amine groups can be calculated by measuring the amine value of the polyamide resin.

Specific examples of the polyamide (A) include 6-nylon, 66-nylon, 610-nylon, 11-nylon, 12-nylon, 6/66 copolymer nylon, and 6/610 copolymer nylon. Nylon, 6/11 copolymer nylon, 6/12 copolymer nylon, 6/66/11 copolymer nylon, 6/66/12 copolymer nylon, 6/66/11/12 copolymer nylon, 6/66/610 / 11/12 Copolymer nylon and so on. These polymers or copolymers may be used alone or as a mixture of two or more. From the viewpoints of the stability and handling properties of the sizing agent for reinforcing fibers of the present invention, among them, polyamine having water solubility is preferable, and oxygen is preferably contained in the main chain of these polymers or copolymers. Polyalkylene is a water-soluble polyamine. The term "water-soluble" as used herein means that 1 part by mass or more can be completely dissolved in 100 parts by mass of water at 20 ° C.

The manufacturing method of the said polyamine (A) uses a well-known method. Examples thereof include methods such as polycondensation of diamine, dicarboxylic acid, ω-amino-ω ′ carboxylic acid, and ring-opening polymerization of cyclic lactam. Here, the polymerization regulator at the time of polycondensation or ring-opening polymerization uses a specific amount of a dicarboxylic acid or a monocarboxylic acid, whereby the aforementioned polyamide resin can be easily produced.

Specific examples of the diamine include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1 , 8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, phenylenediamine, m-xylylenediamine, diethylene glycol amine, triethylene glycol Diamine, tetraethylene glycol diamine, dibutylene glycol diamine, tributylene glycol diamine, tetrabutylene glycol diamine, polyethylene glycol or polypropylene glycol terminal amine compounds, etc. The water-soluble polyamidoamine having an oxyalkylene group in the chain is particularly preferably a terminal amine compound of polyethylene glycol.

Specific examples of the dicarboxylic acid component include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. , Glutaric acid, pimelic acid, nonanedicarboxylic acid, decanedicarboxylic acid, tetradecanedicarboxylic acid, octadecanedicarboxylic acid, fumaric acid, xylene dicarboxylic acid, and the like.

Specific examples of the lactam compound include ε-caprolactam, ω-laurolactam, and the like. Specific examples of the amine carboxylic acid component include 6-aminocarboxylic acid and 11-amine undecyl. Alkanoic acid, 12-aminododecanoic acid, etc.

As a specific example of the dicarboxylic acid used as the said polymerization regulator, the same thing as the said dicarboxylic acid is mentioned. Specific examples of the monocarboxylic acid include hexanoic acid, heptanoic acid, nonanoic acid, undecanoic acid, and dodecanoic acid.

[Carbodiimide-containing compound (B)]

The carbodiimide group-containing compound (B) is a component that imparts fiber bundling property and adhesiveness to a matrix resin to the sizing agent for reinforcing fibers of the present invention.

It is generally known that a carbodiimide compound self-crosslinks by heat and reacts with an active hydrogen compound. In a drying step after the reinforcing fiber of the present invention is coated with the sizing agent on the reinforcing fiber, the carbodiimide is dried. The base is self-crosslinked and reacts with the terminal carboxyl group and amine group of the polyamide (A) and covers the surface of the fiber, thereby improving the fiber bunching property. In addition, since the carbodiimide group can react with and bind to the matrix resin, the adhesion to the matrix resin is improved.

The carbodiimide compound used in the present invention may first be dispersed in an aqueous solvent with a dispersant, and examples thereof include aromatic or aliphatic carbodiimide represented by the following general formula (1) As the compound, such a carbodiimide compound or the like is dispersed in an aqueous solvent using an emulsifier, and the carbodiimide compound in the sizing agent for reinforcing fibers of the present invention can be used.

R ² -NCN- (R ¹ -NCN) _n -R ² (1) (In the formula (1), R ¹ represents m- or p-tetramethylxylene diisocyanate, 4,4'-dicyclohexyl Residues of selected diisocyanate compounds in the group of methane diisocyanate, isophorone diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-toluene diisocyanate, R ² represents a residue of a monoisocyanate compound selected from the group consisting of cyclohexyl isocyanate, phenyl isocyanate, and hexamethylene isocyanate, and n represents an integer of 2 to 30.)

In the above formula, if n, which represents the average degree of polymerization, is less than 2, the number of carbodiimide groups is insufficient, which is not preferable from the viewpoint of reactivity. In addition, when it exceeds 30, the reactants in the carbodiimide synthesis are hardened and gelled, which is not good.

Examples of the carbodiimide compound of the present invention include a water-soluble or self-emulsifying type. For example, a carbodiimide compound having a hydrophilic segment introduced at a carbodiimide terminal as shown in the following general formula (2) may be mentioned. When such a carbodiimide compound is used in the present invention, it can be dissolved in an aqueous solvent or self-emulsified in an aqueous solvent.

Z-OOC-NH- (R ³ -NCN) _n -R ³ -NH-COO-Z (2) (In formula (2), R ³ represents m- or p-tetramethylxylene diisocyanate, 4 , 4'-Dicyclohexylmethane diisocyanate, isophorone diisocyanate residues of the selected diisocyanate compound, Z represents the hydrophilic segment, and n represents an integer from 2 to 30.)

In the above formula, if n, which represents the average degree of polymerization, is less than 2, the number of carbodiimide groups is insufficient, which is not preferable from the viewpoint of reactivity. In addition, when the carbodiimide synthesis exceeds 30, curing and gelation of the reactants are not satisfactory, and the n value is mainly used to determine whether the carbodiimide compound is water-soluble or self-emulsifying.

Z in the above formula showing a hydrophilic segment is not particularly limited, and the following examples are suitably used.

(a) Anionic

First, Z may be a residue of an alkyl sulfonate having at least one reactive hydroxyl group represented by the following general formula (3). Specific examples of the alkyl sulfonate include sodium hydroxyethane sulfonate or sodium hydroxypropane sulfonate, and particularly preferred is sodium hydroxypropane sulfonate.

R ⁵ -SO ₃ -R ⁴ -OH (3) (In the formula (3), R ⁴ represents an alkylene group having 1 to 10 carbon atoms, and R ⁵ represents an alkali metal.)

(b) Cationic

Examples of Z include a quaternary salt of a residue of a dialkylamine alcohol represented by the following general formula (4). Specific examples of the dialkylamino alcohol include 2-dimethylaminoethanol, 2-diethylaminoethanol, 3-dimethylamino-1-propanol, and 3-diethylamino-1-propane Alcohol, 3-diethylamino-2-propanol, 5-diethylamino-2-propanol, or 2- (di-n-butylamino) ethanol, and 2-dimethylaminoethanol is particularly preferred.

(R ⁶ ) ₂ -NR ⁷ -OH (4) (In formula (4), R ⁶ represents a lower alkyl group having 1 to 4 carbon atoms, and R ⁷ represents an alkylene group or oxyalkylene group having 1 to 10 carbon atoms. .)

The hydrophilic segment formed by the above-mentioned dialkylamine alcohol is a known fourth-stage reaction by reacting carbodiimide with the above-mentioned dialkylamine alcohol at the isocyanate terminal with dimethyl sulfuric acid or methyl p-toluenesulfonate. The chemical agent is quaternized and introduced, as shown in the following general formula (5).

(In formula (5), R ⁶ and R ^{7 are} as described above, and R ′ is a group derived from a quaternary agent.)

(c) Non-ionic

Examples of Z include poly (alkylene oxide) residues in which the alkoxy terminal of at least one reactive hydroxyl group represented by the following general formula (6) is blocked. Specific examples of the poly (alkylene oxide) include poly (ethylene oxide) monomethyl ether, poly (ethylene oxide) monoethyl ether, and poly (ethylene oxide / propylene oxide) monomethyl ether. Ether, poly (ethylene oxide / propylene oxide) monoethyl ether, and poly (ethylene oxide) monomethyl ether is particularly preferred.

R ^8- (O-CHR ⁹ -CH ₂ ) _m -OH (6) (In the formula (6), R ⁸ represents a lower alkyl group having 1 to 4 carbon atoms, R ⁹ represents a hydrogen atom or a methyl group, and m represents 4 An integer up to 30.)

The amount of the chemical formula per 1 mol of carbodiimide group of the aforementioned carbodiimide-containing compound (B) is preferably 300 to 600, more preferably 350 to 550. When it is less than 300, the crosslinking density is too high and the abrasion resistance is insufficient. On the other hand, when it exceeds 600, the reactivity is low, and the effects of the present invention cannot be sufficiently obtained.

Water (C) is a medium in which the polyamide resin (A) and the carbodiimide-containing compound (B) are dissolved or dispersed, and various types of water such as tap water, soft water, industrial water, ion-exchanged water, and pure water can be used. Soft water, ion-exchanged water, and pure water are preferred.

[Sizing agent for reinforcing fibers]

The sizing agent for reinforcing fibers of the present invention is obtained by dissolving the aforementioned polyamide resin (A) and the carbodiimide-containing compound (B) in an aqueous solvent or emulsifying and dispersing it in water.

When emulsified and dispersed, the average particle diameter is preferably less than 10 μm, more preferably less than 5 μm, and even more preferably less than 2 μm. When the average particle diameter exceeds 10 μm, it cannot uniformly adhere to the reinforcing fibers, and the sizing agent itself may be separated within a few days, which results in poor storage stability and impracticality. The average particle diameter of the present invention refers to an average value calculated by a particle size distribution measured by a laser diffraction / scattering type particle size distribution measuring device (LA-910 manufactured by Horiba).

From the viewpoints of human safety during operation, prevention of disasters such as fire, and prevention of natural environment pollution, the sizing agent of the present invention must contain water. That is, water is the main solvent. Organic solvents such as methanol, ethanol, isopropanol, acetone, and methyl ethyl ketone can be used as long as the effects of the present invention are not impaired.

Examples of components other than those described above that constitute the sizing agent of the present invention include various surfactants, various smoothing agents, antistatic agents, preservatives, penetrants, antioxidants, flame retardants, antibacterial agents, and crystal nucleating agents. And antifoaming agents, etc., can be used singly or in combination of two or more kinds.

In particular, when a water-insoluble or poorly-soluble resin component is contained in the sizing agent of the present invention, a surfactant is used as an emulsifier. On the other hand, water-based emulsification can be performed efficiently.

The surfactant is not particularly limited, and a known one can be suitably selected from nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. The surfactant may be used alone or in combination of two or more.

In the foregoing polyamide resin (A), the weight ratio of the non-volatile content of the sizing agent is preferably 70 to 99.9% by weight, more preferably 80 to 99% by weight, and still more preferably 90 to 95% by weight. . When it is less than 70% by weight, the bundling property is insufficient. When it exceeds 99.9% by weight, the carbodiimide group-containing compound (B) is insufficient, and adhesiveness is insufficient.

In addition, the nonvolatile matter in the present invention refers to an absolutely dry component when a sizing agent is heat-treated at 105 ° C. to remove a solvent or the like and reach a constant amount.

The weight ratio (B / A) of the aforementioned carbodiimide group-containing compound (B) relative to the aforementioned polyamide resin (A) is preferably from 0.1 to 30% by weight, more preferably from 1 to 20% by weight, and More preferably, it is 5 to 15% by weight. When it is less than 0.1% by weight, the adhesiveness is insufficient. When it exceeds 30% by weight, the abrasion resistance is insufficient.

The non-volatile matter concentration of the sizing agent for reinforcing fibers of the present invention is not particularly limited, and is suitably selected in consideration of the stability of the aqueous solution or the aqueous dispersion, the viscosity of the product that is easy to handle, and the like. In consideration of the product transportation cost, etc., the weight ratio of the non-volatile matter in the entire sizing agent is preferably 10 to 60% by weight, more preferably 15 to 60% by weight, and particularly preferably 20 to 50% by weight.

In addition, in the entire sizing agent for reinforcing fibers, the total weight ratio of water and nonvolatile matter is preferably 90% by weight or more, and more preferably 95% by weight or more. It is more preferably 99% by weight or more, and particularly preferably 100% by weight. When it is less than 90% by weight, that is, when the above-mentioned organic solvent or other low-boiling compounds that are not nonvolatile and remain during heat treatment are 10% by weight or more, the safety of the human body during operation and the prevention of natural environmental pollution are considered. Looks worse.

[Reinforced fiber thread and its manufacturing method]

The reinforcing fiber yarn of the present invention is obtained by attaching the above-mentioned sizing agent for reinforcing fibers to a raw synthetic fiber yarn, and is used to reinforce a thermosetting or thermoplastic matrix resin. The reinforcing fiber yarn of the present invention has excellent adhesion to a thermosetting or thermoplastic matrix resin. In addition, since the reinforcing fibers having excellent bundling and abrasion resistance are treated with a sizing agent, it is possible to suppress the fiber filaments from being broken or fluff in the step of manufacturing the reinforcing fiber filaments, and it is possible to suppress the degradation of fiber quality or manufacturing problems.

The amount of non-volatile matter attached to the raw material synthetic fiber thread can be appropriately selected, as long as it is a necessary amount for the reinforcing fiber yarn to have the required function, and its adhesion amount is preferably 0.1 to relative to the raw material synthetic fiber thread. 20% by weight. In the continuous fiber state, the adhesion amount of the synthetic fiber yarn is preferably 0.1 to 10% by weight, and more preferably 0.5 to 5% by weight relative to the raw material synthetic fiber yarn. The yarn cut to a specific length is more preferably 0.5 to 20% by weight, and still more preferably 1 to 10% by weight.

If the amount of the sizing agent is small, it is difficult to obtain the effects of the present invention on uniform adhesion, adhesion, and the like. In addition, the bundling property of the reinforcing fiber filaments is insufficient, and the operability is deteriorated. In addition, if the amount of sizing agent is too large, the synthetic fiber thread becomes too rigid, which will worsen the operability, and the resin will be used for composite molding. Impregnation becomes worse and worse.

The manufacturing method of the reinforced fiber thread of the present invention includes the following steps: a preparation step, which is a preparation treatment solution containing the aforementioned sizing agent, and the weight ratio of the nonvolatile matter is 0.5 to 10% by weight, and water and nonvolatile matter The total weight ratio is 90% by weight or more; the attaching step is to attach the treatment liquid to the raw synthetic fiber filaments so that the non-volatile matter adhered to the raw synthetic fiber filaments in an amount of 0.1 to 20 wt%.

In the preparation step, the weight ratio of the non-volatile content in the treatment liquid is more preferably 1 to 10% by weight, and still more preferably 2 to 5% by weight. The total weight ratio of water and nonvolatile matter is more preferably 95% by weight or more, still more preferably 99% by weight or more, and particularly preferably 100% by weight.

In the attaching step, the preferred amount of non-volatile content is as described in the previous paragraph. The method of attaching the sizing agent to the raw synthetic fiber thread is not particularly limited, and may be a method of attaching the sizing agent to the raw synthetic fiber thread by a lip roll method, a roll dipping method, a spray method, or other known methods. Among these methods, the roller dipping method is preferred because it can uniformly adhere the sizing agent to the raw synthetic fiber strands.

The drying method of the obtained adherend is not specifically limited, For example, a heating roll, a hot air, a hot plate, etc. can be used for drying.

In addition, when the sizing agent of the present invention is adhered to the raw material synthetic fiber thread, all the constituent components of the sizing agent may be mixed and then adhered, or the constituent components may be divided into two or more stages to be adhered. In addition, as long as the effect of the present invention is not inhibited, thermosetting resins such as epoxy resin, vinyl ester resin, and phenol resin, and / or amines other than the polymer component of the present invention can be used. Thermoplastic resins such as ethyl acetate resin, polyester resin, nylon resin, and acrylic resin are adhered to the raw synthetic fiber yarn.

The reinforcing fiber yarn of the present invention is a reinforcing fiber used as a composite material using various thermosetting resins or various thermoplastic resins as matrix resins. The use form may be a state of continuous fibers or a state of being cut to a specific length.

Synthetic fibers that can be used for the synthetic fiber threads of the sizing agent (raw material) of the present invention include various inorganic fibers such as carbon fibers, glass fibers, and ceramic fibers, aramid fibers, polyethylene fibers, and polyparaphenylene terephthalate. Various organic materials such as ethylene formate fiber, polybutylene terephthalate fiber, polyethylene naphthalate fiber, polyarylate fiber, polyacetal fiber, PBO fiber, polyphenylene sulfide fiber, polyketone fiber, etc. fiber. From the viewpoint of the physical properties of the obtained fiber-reinforced composite material, the synthetic fiber is preferably made of carbon fiber, aramid fiber, polyethylene fiber, polyethylene terephthalate fiber, polybutylene terephthalate fiber, poly At least one selected from the group consisting of ethylene naphthalate fiber, polyarylate fiber, polyacetal fiber, PBO fiber, polyphenylene sulfide fiber, and polyketone fiber, and more preferably carbon fiber.

〔Fiber reinforced composite material〕

The fiber-reinforced composite material of the present invention contains a thermosetting matrix resin or a thermoplastic matrix resin, and a synthetic fiber strand as the aforementioned reinforcing fiber. Since the synthetic fiber threads are treated with the sizing agent of the present invention, the sizing agent has good affinity with the synthetic fiber threads and the matrix resin, and is a fiber-reinforced composite material having excellent adhesion.

Here, the thermosetting matrix resin refers to a matrix composed of a thermosetting resin. The resin may contain one kind or two or more kinds. The thermosetting resin is not particularly limited, and examples thereof include epoxy resin, phenol resin, unsaturated polyester resin, vinyl ester resin, acrylic resin, cyanate resin, and polyimide resin.

The thermoplastic matrix resin refers to a matrix resin composed of a thermoplastic resin, and may contain one kind or two or more kinds. The thermoplastic matrix resin is not particularly limited, and examples thereof include polyolefin resins, polyamide resins, polycarbonate resins, polyester resins, polyacetal resins, ABS resins, phenoxy resins, and polymethyl methacrylate resins. , Polyphenylene sulfide resin, polyether sulfide imine resin, polyether ketone resin, etc. Among these, the polyamine resin which has a high adhesion improvement effect by the sizing agent of this invention is preferable. Here, the polyamidoamine resin refers to a polymer having a plurality of amido groups in the main chain synthesized from a dibasic fatty acid and a diamine, an omega-amino acid, a lactam, or a derivative thereof. The compound also includes a homopolymer or a copolymer (interpolymer) and the like. In addition, it may be a modified body in which a substituent is introduced into a main chain or a terminal.

For the purpose of further improving the adhesion with synthetic fiber yarns, the thermosetting matrix resin or the thermoplastic matrix resin may be partially or completely modified.

The manufacturing method of the fiber-reinforced composite material is not particularly limited, and known methods such as injection molding of short fibers or long fiber spindles, compression molding of UD sheets or fabric sheets, and other winding moldings can be used.

The content of the synthetic fiber threads in the fiber-reinforced composite material is not particularly limited, and may be appropriately selected according to the type and shape of the fiber, the type of the thermoplastic matrix resin, etc., and is preferably 5 to 70 weight based on the obtained fiber-reinforced composite material. %, More preferably 20 to 60% by weight.

(Example)

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to the examples described. In addition, the% and part shown in the following examples show "weight%" and "weight part", without being specifically limited. The measurement of each characteristic value was performed by the method shown below.

<Viscosity>

The melt viscosity of the polyamide (A) was measured at a temperature of 150 ° C. using a cone-plate viscometer (I.C.I CON & PLATE VISCOMETER, manufactured by RESEARCH EQUIPMENT).

<Bundling>

Sizing each sizing agent (diluted with water to 3%, adhesion rate 1%) on carbon fiber, and cut with a utility knife to 10 5mm lengths, and visually observe whether there is loosening at this time. Judging by the following evaluation criteria, ◎ and ○ were passed.

：: Two or less pieces were released.

○: 3 to 4 pieces are loosened.

△: 7 to 5 pieces were loosened.

×: 8 or more pieces were loosened.

<Abrasion resistance>

Using a TM-type friction entanglement force tester TM-200 (manufactured by Daiei Scientific Seiki Co., Ltd.), three mirror-chrome plated stainless steel needles arranged in a zigzag configuration and rubbing the precursor wire (12K) 1000 times with 50g tension Movement speed is 300 times / minute), and the state of fluff generation of the precursor thread is visually determined using the following criteria. According to the following indicators, ◎ and ○ are acceptable.

：: No fluff was observed at all before the rubbing.

○: Although several fluffs were observed, the abrasion resistance was good.

(Triangle | delta): A little more fluff is generated and abrasion resistance is a little inferior.

×: A large amount of fluff was generated and a significant single yarn break was observed. Poor abrasion resistance.

<Dynamic surface tension (uniform adhesion)>

The sizing agent was diluted with water so as to become a 3% by weight non-volatile matter aqueous solution, and a bubble generation interval (orifice plate) was applied at 25 ° C (pore plate) at 25 ° C using a pressurized void type dynamic surface tension meter (BP-2, manufactured by Kurss). The dynamic surface tension measurement is performed within the range, and the dynamic surface tension measurement value at 100 msec of the bubble generation interval (orifice plate) is read. According to the following indicators, ◎ and ○ are acceptable.

：: Less than 64.0 mN / m.

○: 64.0 mN / m or more and less than 66.0 mN / m.

Δ: 66.0 mN / m or more and less than 68.0 mN / m.

×: 68.0 mN / m or more.

<Adherence>

Adhesion was evaluated by the droplet method using a composite material interface characteristic evaluation device HM410 (manufactured by Toei Industries Co., Ltd.).

The carbon fiber filaments were taken out from the carbon fiber filaments produced in the examples and comparative examples, and installed in a composite material interface characteristic evaluation device. Liquid droplets of the polyamide resin T-663 (manufactured by Toyobo Co., Ltd.) melted on the device were formed on carbon fiber filaments, and cooled sufficiently at room temperature to obtain a measurement sample. The measurement sample was set in the device again, the liquid droplet was clamped by the device blade, the carbon fiber filament was moved on the device at a speed of 0.06 mm / minute, and the measurement was performed when the carbon fiber filament was pulled out of the liquid droplet. The maximum pull-out load F.

The interface shear strength τ was calculated from the following formula, and the adhesion between the carbon fiber filament and the polyamide resin was evaluated.

Interfacial shear strength τ (unit: MPa) = F / πdl.

(F: maximum pull-out load. D: diameter of the carbon fiber filament. L: particle diameter of the droplet in the pull-out direction.)

According to the following indicators, ◎ and ○ are acceptable.

：: 50.0 MPa or more.

：: 45.0 MPa or more and less than 50.0 MPa.

△: 35.0 MPa or more and less than 45.0 MPa.

×: Less than 35.0 MPa.

The following components (A-1 to C-1) were used and mixed at the ratios (parts by weight) described in Tables 1 and 2 to obtain reinforcing fibers for Examples 1 to 11 and Comparative Examples 1 to 12, respectively. Slurry. In addition, the molecular weight means the number average molecular weight of a polymer unless otherwise stated.

A-1: Water-soluble polyamidine, melt viscosity 4000mPa at 150 ℃. s.

A-2: Water-soluble polyamidine, melt viscosity 1000mPa at 150 ℃. s.

A-3: Water-soluble polyamidine, melt viscosity 8000mPa at 150 ℃. s.

A-4: Water-insoluble polyamidine, melt viscosity 800mPa at 150 ℃. s.

B-1: Polycarbodiimide emulsion (40% by weight of active ingredient, viscosity: 10mPa.s, amount of chemical formula per 1mol of carbodiimide group: 445).

B-2; polycarbodiimide aqueous solution (40% by weight of active ingredient, viscosity: 100mPa.s, chemical formula amount per 1mol of carbodiimide group: 410).

C-1: ion-exchanged water.

X-1: liquid epoxy resin (viscosity at 25 ° C: 13,500 mP · s).

X-2: Polyamidine, melt viscosity 20000 mPa at 150 ° C. s.

X-3: Water-soluble polyamidine, melt viscosity at 150 ° C 80mPa. s.

[Synthesis of Polyamide]

(Synthesis example A-1)

In a container equipped with a stirring device, 112 parts of polyetherdiamine (molecular weight 400), 30.7 parts of adipic acid, 45 parts of ε-caprolactam, and 0.6 parts of p-toluenesulfonic acid were added, and polycondensation was carried out at 220 ° C under stirring. 14 hours, and polyamine (A-1) was obtained. The melt viscosity of the obtained polyamide (A-1) at 4000C was 4000 mPa. s.

(Synthesis example A-2)

A polyamine (A-2) was obtained in the same manner as in Synthesis Example A-1 except that the reaction temperature was changed to 200 ° C. The obtained polyamidoamine (A-2) had a melt viscosity of 1000 mPa at 150 ° C. s.

(Synthesis example A-3)

A polyamine (A-3) was obtained in the same manner as in Synthesis Example A-1 except that the amount of adipic acid in the raw material was changed to 28.0 parts. The obtained polyamidoamine (A-3) had a melt viscosity of 8000 mPa at 150 ° C. s.

(Synthesis example A-4)

In an autoclave equipped with a stirring device, 120 parts of 6/66/12 copolymerized nylon, 179.6 parts of water, and 0.4 part of sodium hydroxide were added, and the temperature was increased to 150 ° C. under nitrogen reflux and stirring. After the internal temperature was kept at 150 ° C and further stirred for 30 minutes, the contents were cooled to 50 ° C and taken out from the autoclave to obtain a polyamine resin aqueous dispersion (A- 4). The polyamide resin component of the obtained polyamide resin aqueous dispersion (A-4) had a melt viscosity of 800 mPa at 150 ° C. s.

(Synthesis example X-2)

In a reaction vessel equipped with a stirring device, 1,000 parts of polyetherdiamine (molecular weight 900), 159 parts of adipic acid, 375 parts of ε-caprolactam, and 23 parts of phosphoric acid aqueous solution were added. Polymerization was performed at 230 ° C for 4 hours. Thereafter, polymerization was performed under reduced pressure for 1.5 hours, thereby obtaining a polymer. Thereafter, the inside of the container was decompressed by a pressure-adjusting device at 230 ° C for 1 hour, and polymerization was performed at 230 ° C for 0.5 hours to obtain polyamine (X-2). The obtained polyamidoamine (X-2) has a melt viscosity of 20,000 mPa at 150 ° C. s.

(Synthesis example X-3)

A polyamine (X-3) was obtained in the same manner as in Synthesis Example A-1 except that the reaction time was changed to 1 hour. The melt viscosity of the obtained polyamide (X-3) was 80 mPa at 150 ° C. s.

[Examples 1 to 11, Comparative Examples 1 to 12]

The polyamidoamine, polycarbodiimide compound, water, and other components produced above were mixed and stirred so as to become the weight ratio of Tables 1 to 2 to prepare a sizing agent. Using the obtained sizing agent, uniform adhesion was evaluated by the aforementioned method.

Next, the sizing agent-treated carbon fiber filaments (fineness 800tex, 12,000 filaments) were dipped / impregnated into the prepared sizing agent, and then dried at 105 ° C for 15 minutes to obtain a non-sizing agent. The amount of parts adhered to the carbon fiber yarn was 1% by weight based on the size-treated carbon fiber yarn. The present yarn was evaluated for abrasion resistance, bunching property, and matrix resin adhesion by the aforementioned methods.

As can be seen from Tables 1 to 2, the sizing agents in the examples have excellent abrasion resistance, bunching, uniform adhesion, and adhesion. also, The sizing agents shown in the comparative examples did not meet any of the above-mentioned required characteristics.

Claims (9)

A sizing agent for reinforcing fibers, which contains polyamidoamine (A), a carbodiimide-containing compound (B), and water (C). The polyamidoamine (A) has a melt viscosity of 150 ° C at 100 ° C. To 15000mPa. s. The compound (B) has two or more carbodiimide groups in the molecule. The sizing agent for reinforcing fibers according to item 1 of the scope of the patent application, wherein the polyamide (A) is a water-soluble polyamide. The sizing agent for reinforcing fibers according to item 1 or 2 of the scope of the patent application, wherein the polyamine (A) is a polycondensate of an amine and a carboxylic acid and has an oxyalkylene group. The sizing agent for reinforcing fibers according to any one of claims 1 to 3, wherein the weight ratio of the aforementioned carbodiimide-containing compound (B) to the aforementioned polyamide (A) ( B / A) is 1 to 30% by weight. The sizing agent for reinforcing fibers according to any one of claims 1 to 4, wherein the chemical formula of the carbodiimide group-containing compound (B) per mol of carbodiimide group is 300 to 600. A reinforcing fiber yarn is obtained by adhering a sizing agent for reinforcing fibers according to any one of claims 1 to 4 to a raw material reinforcing fiber yarn. The reinforcing fiber yarn according to item 5 of the scope of patent application, wherein the aforementioned reinforcing fiber is a carbon fiber. A fiber-reinforced composite material containing a matrix resin, and as The reinforced fiber thread according to the fifth or sixth aspect of the invention. The fiber-reinforced composite material according to item 7 of the patent application scope, wherein the matrix resin is a thermoplastic resin.